To Heart (1999)

For as long as Akari can remember, she and Hiroyuki have always been friends. But with time, everything changes, and her feelings have turned into something more. As a new semester of high school begins, will the two childhood friends come closer together or drift further apart? Join Hiroyuki, Akari and all their friends—the bubbly Shiho, the quiet Serika, the lovely Kotone, and more—in this heartwarming tale of love, relationships and friendship! (Source: RightStuf)